在Block里使用self调用方法

__weaktypeof(*&self) wSelf = self;//

[previewC setDidFinishPreviewBlock:^(NSArray<XMNAssetModel *> *selectedAssets) {

    __weaktypeof(*&self) self = wSelf;//

    self.selectedAssets = [NSMutableArrayarrayWithArray:selectedAssets];

    [self.bottomBarupdateBottomBarWithAssets:self.selectedAssets];

    [self.collectionViewreloadData];

}];